1. Field of the Invention
The present invention relates to a lens driving unit and a camera module comprising the same, and more particularly, to a lens driving unit that generates a precise linear motion in a spatially limited structure by using a bending vibration piezoelectric motor so as to perform an auto-focusing (AF) function or a zooming function, and a camera module comprising the lens driving unit.
2. Description of the Related Art
Recently portable electronic devices have increasingly employed a camera module having an auto-focusing (AF) function or a zooming function. Cellular phones employ small and thin camera modules since the thicker the camera modules are, the thicker the cellular phones are.
A lens barrel supporting a lens is moved along a guide unit in order to perform the AF function or the zooming function. A stepping motor or a piezoelectric motor may be used as a driving unit for moving the lens barrel along the guide unit. The stepping motor is driven by a step waveform changed from an input pulse, is controlled and operated by an electronic circuit by using direct current power, and shows a fast response to a location control in a short distance.
However, the stepping motor needs a lot of components due to the sizes of a reduction gear, a connecting area, and itself, which may result in increasing the size of an operation module. Also, the increase in the number of components may increase manufacturing cost.